Truing attachment



-Aug. 22, 1939. c. HERFURTH mums ATTACHMENT Filed Dec. 6, 1937 6Sheets-Sheet 1 BIC O 1 fl- 1939- c. HERFURTH TRUING ATTACHMENT 6Sheets-Sheet 2 Filed Dec. 6, 1937 INVENIOR. C HA ELES HER'FUR TH WW.

ATTORNEY.

Aug. 22, 1939. Q mH 2,170,304

' TRUING ATTACHMENT jsFiled Dec. 6, 1.937 14 6 Sheets-Sheet 4 AI/I. v////V" INVENTOR. CHARLES HERFURTH BY WWW ATTORNEY.

Aug. 22, 1939. v c. HERFURTH 2,170,304

I mums ATTACHMENT I Filed Dec. 6: 1937 6 Sheets-Sheet 5 v INVENTOR.

6 HA IZLES HERFl/l? TH I ATTO EY.

0 t n\\ Or m fiw fi .mw 7 1 1 9 w NE 2 w H. a 6 M H Cr H w Tn Run um w YFM B m GD Hm v GEM N am Aug. 22, 1939.

ATTORNEY.

Patented Aug. 22, 1939 TRUING ATTACHMENT Charles Heriurth, Cincinnati,Ohio, assignor to Cincinnati Grinders Incorporated, Cincinnati. Ohio, acorporation of Ohio Application December 6, 1937, Serial No. 178,225

3 Claims.

This invention relates to grinding machines and more particularly toimprovements in truing attachments therefor.

One of the objects of this invention is to provide an improved compacttruing attachment for grinding machines.

Another object of this invention is to provide an improved operating andcontrol mechanism for a truing attachment which is self-contained in theattachment.

A further object of this invention is to provide a simplified'poweroperable control mechanism for a truing attachment which-will executeone stroke at the will of the operator.

- An additional object of this invention is to provide an improvedtruing attachment which is angularly adjustable for producing straightbeveled surfaces on the wheel, or which may be contour controlled forproducing other than straight surfaces on the wheel.

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification considered inconjunction with the accompanying drawings illustrative of oneembodiment thereof, but it will be understood that any modifications maybe made" thereof.

Figure 3 is a section through the mechanism as viewed on the line 3-3-0!Figure 2.

Figure 4 is a section through the control valve mechanism as viewed onthe line 4-4 of Figure 2.

Figure 5 is a section on the line 5-5 of Figure 2.

Figure 6 is a section on the line 6-6 of Figure 2.

Figure '7 is a section on the line 1-1 of Figure 2.

Figure 8 is a section on the line 8-8 of Figure 2..

Figure 9 is a section on the line 3-! of Figure 2.

Figure 10 is an elevational view of the contour control mechanism asviewed on the line il lfl of Figure 1.

Figure 11 -8. of Figure 10.

detail section on the line u Figure 12 is a diagrammatic view of thehydraulic control circuit.

Figure 13 is a section on the line I3l3 of Figure 5. I

Figure 14 is a section on the line ll of 5 Figure 5.

Referring to Figure 1 of the drawings, the reference numeral Iiiindicates a fixed part of a machine tool, having a guide surface ll,upon which is adjustably mounted a bracket l2. A 10 pair of T-bolts i3,mounted in a T-slot it formed in the support II, and passing through"the bracket l2, serve to secure the bracket'to the fixed part ill ofthe'machine. By means of this arrangement, the bracket may be adjustedto- 5 wards and from the axis i5 of a grinding wheel IS.

The bracket is provided with a top supporting surface l'l upon which ismounted a saddle ii. i As shown in Figure 3, a pivot pin is is fixed inthe bracket i2 and projectsinto a hole formed 20 in the under side ofthe saddle to serve as a pivot point about which the saddle may be movedfor changing the angular relation of the guide surfaces 2! formed on thetop side of the saddle with respect to the axis i5 of the grinding 2wheel. Clamping screws 22 passing through elongated slots 23, in thesaddle and threaded in the bracket i2 serve to clamp the saddle indifferent angular positions. As shown in Figure 2, graduation marks 24are formed on the rear of the bracket i2 for cooperation with a zeromark 25 formed on the saddle to indicate the amount of angularadjustment.

it slide 26, having guide surfaces 21 shaped to cooperate with theguideways 2|, is mounted z on the saddle for relative sliding movementin l a rectilinear path. The slide 26 has a bore 28 formed therein forreceiving a tubular member.

29 which carries the truing'tooljll. The tubular member 29 is adapted toslide crosswise relative to the slide 26 and to this endls normallyurged in one direction by a spring 3i which is interposed between a lug32, integral with the tubular member, and a lug 33 integral with theslide 26.

To control this movement the slide 26 has a de- 5 pending bracket 3, inwhich is rotatably mounted a roller 35 cooperating with an adjustablecam bar 36 carried by the saddle it. The spring Sl continuouslymaintains the roller 35 5 l in contact with the cam bar. As shown inFigure 11, the cam bar 35 is held in place by a pair of clamping members31, which have radially extending lugs 38 which overlapreducedportionson the ends of the cam bar. Clamping screws 3! pass through theclamping members and are '55 threaded in a longitudinally adjustable cambar carrier 40. l

The cam bar is made flexible so that it may be adjusted to impartdifierent degrees of curvature or camber to the face of the grindingWheel. This adjustment is efiected by a bolt 4| which is threaded in thecarrier 40 about midway between the ends of the cam bar and so that thehead oi the bolt will engage the cam bar and deflect or bend the same. Arecess 42 is formed in the carrier 40 around the head of the bolt 4| topermit insertion of a suitable tool for rotating the nut.

Since different widths of grinding wheels may be applied to the spindlewithin certain limits, and since it is usually desirable that the highpoint of a camber should be in the center of the grinding wheel, thecarrier 40 is adjustable so that the axis of the bolt 4| will lie in aplane passing through the central plane of the grinding wheel regardlessof its width. This adjustment is accomplished by providing elongatedslots 43 in each end of the carrier through which clamping bolts 44threaded in the saddle l8 will pass, so that when these bolts areloosened, the carrier may be adjusted longitudinally. To facilitatelarge adjustments additional threaded holes 45 may be provided in thesaddle 18 for receiving thebolts 44. To assist the operator in makingthese adjustments, the carrier 40 is provided with a depending pointer46, which cooperates with a suitably marked scale 41 attached to thesaddle l8, as shown in Figure 10. It.will now be evident that when thecamber determining screw 4| is adjusted out of engagement with the cambar 36, that the same will be straight, and that the diamond tool willtravel a rectilinear path; and that when the screw is adjusted to flexthe camber bar 36, that the tool will travel a curved path, the spring3| always holding the follower 35 against the cam bar.

Power operable means have been provided for reciprocating the slide 26relative to the saddle Hi. This power operable means is hydraulic innature, and the actuating and control means are very compactly arrangedin the saddle. This compact arrangement is obtained by providing alongitudinal bore 48 in the saddle substantially midway between its topand bottom surfaces and extending longitudinally through the same inparallel relation to the guide surfaces formed thereon. This bore isdivided into a cylinder por-- tion and a valve portion. Within thecylinder portion is a piston 49 which is connected by a piston rod 58 toa bracket depending from the slide 26. Cylinder head 52 is fitted in oneend of the bore 48 for closing the same and for supporting the pistonrod 58 which passes through it.

A valve housing 53 having a solid end 54 is inserted in the other end ofthe bore 48, and serves as a closure for that end of the bore in orderto form a closed cylinder for operation of the piston 49.

The valve housing includes a tubular member 55 which fits tightly in thebore 48 and has a series of annular grooves 56, 51, 58, 59 and 69 formedin its periphery. A generally cylindrical valve member 6| is rotatablymounted within the sleeve and this valve member has portions cut awaymidway of its length to form two intersecting vanes 62 and 63 whichdivide the valve into four quadrants 64, 65, B6 and 61. The groove 58 isconnected by an interdrilled passage 58, as shown in Figures 6 and 14,to an external pressure supply pipe 69. As diagrammatically shown inFigure 12, this pipe may be supplied with fluid pressure from a suitablylocated pump lllhaving an intake H through which fluid is withdrawn froma reservoir 12.

Referring to Figure 7, the annular groove 59 is connected by aninterdrilled passage 13 to port 14 located in the right hand end of thecylinder portion. The, annular groove 50, shown in Figure 8, isconnected by an interdrilled passage 15, which is more particularlyshown in Figure 13, to port 16 located in the left hand end of thecylinder portion.

The vanes of the valve are normally held in the position in which theyare shown in Figures 5, 6, 7 and 8 by a detent mechanism which is moreparticularly shown in Figure 9. The plunger is provided with a reducedoperating stem H which extends through the head 18 and provided with anoperating handle 19. Between the head 18 and the enlarged portion of theplunger is keyed a detent plate 89 which has Vshaped notches 8| formedin opposite sides of its periphery. A pair of spring pressed detentplungers 82 are slidably mounted in sleeves 83 which are inserted inopposite sides of the saddle l8 and secured in place by screws 84. Thedetent plate is keyed to the shaft 11 in the proper angular relation sothat when the detent plungers engage the bottom of the V's, as shown inFigure 9, the vanes of the plunger are in the position shown in Figures5, 6, 'l and 8.

To limit rotation of the valve plunger, a limiting groove 85 is cut inthe top of the detent plate and a stop screw' 86 is threaded in thesleeve 55 with a reduced portion projecting into the groove wherebyafter a predetermined angle of rotation of the valve, the reducedportion will contact one end or the other of the groove.

The pressure groove 58, shown in Figure 6, has a pair of diametricallyopposed radial ports 8'! which, it will be noted, lie in a verticalplane and in alignment with opposite ends of the vane 62. The annulargroove 59, shown in Figure '7, has a pair of opposed radial ports 89which lie in a plane substantially 45 out of phase with the plane of theports shown in Figure 6 and in a clockwise direction. The annular groove68 shown in Figure 8 has a pair of opposed ports 98 lying substantially45 out of phase with the pane of the ports shown in Figure 6 but in acounterclockwise direction. It will now be apparent that if the valve isrotated in a clockwise direction, as viewed in Figures 6, 7 and 8, thatthe pressure ports 87 will be connected through quadrantgrooves 65 and5l.to port 99 whereby fluid pressure will flow through port 76 to thecylinder; and if the valve is rotated in a counterclockwise direction,the ports 81 will be connected by quadrant grooves 64 and 66 to ports 89whereby pressure fluid will flow to port I4 of the cylinder.

Additionally, when the valve is rotated clockwise, the quadrant grooves64 and 66 will connect the ports 90 to a pair of diametrically opposedports 9| which, as shown in Figure 5, communicate with annular groove51; and when the valve is rotated counterclockwise, the quadrant grooves65 and 6! will connect the diametrically opposed ports 90 leading fromthe right hand end of the cylinder to ports 9| and thereby to annulargroove 51.

As shown in Figure 5, the annular groove 51 is connected by a passage 92to an adjustable throttle valve indicated generally by the referencenumeral 93. It will be noted that this throttle valve extends at rightangles to the axis thereto, and that the passage 92 is coincident withradial lines of the bore 48 and the valve.

The throttle valve plunger 94 is provided with a spool 95 which isadjustable'relative to the end of passage 92 and in the end of the spoolis a. V-shaped notch 96 which, as it is adjusted toward the left asviewed in Figure 5,'increases the opening to annular groove 91 formed inthe throttle valve plunger and as it is adjusted toward the right,decreases the opening to the annular groove. In other words, this grooveserves to regulate the rate offlow from the exhaust end of the cylinderand thereby regulate the rate of movement of the truing tool across theface of the grinding wheel. The annular groove 91 is in constantcommunication with a port 98 which is connected by an interdrilledpassage 99 to an external exhaust pipe I00, as more particularly shownin Figure 14. This exhaust line may have a check valve l| suitablyplaced therein for maintaining a small back pressure in the connectinglines and thereby maintaining the system full of fluid.

The throttle valve plunger is shown in its greatest feed rate positionin Figure 5, and as it is moved toward the right in that figure, itreduces the feed rate of the truing tool. This adjustment is effected byproviding a threaded portion I02 on the plunger which interengages withthreads I03 formed-in the end of the valve and rotating the same bymeans of a knurled operating knob I04. The operating knob I04 has askirt portion I05 movable relative to a barrel portion I06 integral with-the end of the valve, and by providing suitable graduations on each,the rate of movement of the slide may be calibrated. A

spring I01 is interposed between the end of the valve and the end of theknob for removing any back lash between the screw I02 and the threadsI03. It should now be evident that if the operator throws the lever I9in either direction from its normal central position and holds it thereagainst the action of the spring pressed detents, that the truing toolwill be moved across the face of the grinding wheel at a rate determinedby the setting of the throttle valve, and when he releases the handlethe valve will return to a central position which will stop thismovement. The direction of movement, of course, will be determined bythe-direction in which the operator moves the handle I9 from its centralposition.

In order to prevent excessive pressure building up in the valve when theslide is not being used, the vane 62 is provided with a diametricalpassage I08 which intersects a cross bore I09 that terminates in asecond diametrical bore IIO. This bore terminates in the periphery of aspool I which lies opposite a pair of diametrical ports II2, as moreparticularly shown in Figure 4, which are in communication with anannular groove 56. The groove 56 is connected by an interdrilled passageH3 to the interdrilled passage 99, as more particularly shown in Figure14 Thus the H-shaped passage formed in the interior of the valve plungerserves to connect the pump "to reservoir, audit will be noted in such amanner that the valve plunger is always under hydraulic balance due tothe pairs of diametrically opposed ports.

There has thus been provided an improved compact truing mechanism whichis designed to be built'as a self-contained unit including the necessarymeans for power reciprocating the truing tool, the necessary controlmeans for determining the rate and direction of said movement andvarious adjustable means for determining the shape of the contour to beimparted to the wheel and regardless of variations in'the width of theface thereof.

What is claimed is:

1. In a truing attachment for a rotatable grinding wheel of a grindingmachine, the com bination of a support having a guideway lying in aradial plane with respect to the axis of the grinding wheel, a bracketmounted on said guideway for adjustment in said radial plane, a truingtool carrier, means mounted on the bracket for supporting said carrierfor axial movement in for power shifting said slide and carrier.

2. In a truing attachment for the grinding wheel of a grinding machine,the combination of a bracket having top and bottom surfaces which lie inplanes that intersect, a saddle pivotally mounted on said top surface,guideways formed on the top surface of the saddle and-receiving a slide,and a truing tool carrier supported on the slide for axial adjustmenttransversely of the direction of slide movement, the carrier adjustmentaxis intersecting the plane of the bottom surface of said bracket in theaxis of the grinding wheel whereby said attachment may be mounted on asurface of the machine which lies in a radial plane with respect to theaxis of the grinding wheel and still position the axis of reciprocationof the truing tool in a second radial plane with respect to the axis ofthe grinding wheel.

3. In a truing attachment for a grinding machine, the combination of aSupp rting bracket, a truing tool carrying slide, a saddle interposedbetween the top surface of said bracket and said slide, said saddlehaving parallel top and bottom surfaces, one of which includes guidewaymeans for said slide, a pivotal connection between the bottom surface ofsaidsaddleand the top surface of said bracket for angularly varying thepath of reciprocation of said slide, said saddle having a bore passingtlnrough the same midway between the top and bottom surfaces thereof,means dividing said bore into a hydraulic cylinder and a valve housing,a piston reciprccably mounted in the cylinder and operatively connectedto the slide, a valve mounted in said housing, interdrilled passagesformed .in said saddle connecting said valve respectively .to oppositeends of the cylinder, to exhaust, and to a source of pressure, detentmeans normally positioning said valve to isolate the interdrilledpassages leading to opposite ends of the cylinder and simultaneously toconnect the pressure supplying passage with the exhaust passage, wherebythe slide will remain at rest and manually operable means for movingsaid valve to effect hydraulic operation of said slide.

CHARLES HERFUR'I'H.

